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(11) | EP 2 353 523 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Microcoil vaso-occlusive device with multi-axis secondary configuration |
| (57) A vaso-occlusive device includes a microcoil formed into a minimum energy state secondary
configuration comprising a plurality of curved segments, each defining a discrete
axis, whereby the device, in its minimum energy state configuration, defines multiple
axes. In a preferred embodiment, the secondary configuration-comprises a plurality
of interconnected closed loops defining a plurality of discrete axes. In a second
embodiment, the secondary configuration defines a wave-form like structure comprising
an array of laterally-alternating open loops defining a plurality of separate axes.
In a third embodiment, the secondary configuration forms a series of tangential closed
loops, wherein the entire structure subtends a first angle of arc, and wherein each
adjacent pair of loops defines a second angle of arc. In a fourth embodiment, the
secondary configuration forms a logarithmic spiral. In all embodiments, the device,
in its secondary configuration, has a dimension that is substantially larger than
the largest dimension of the vascular site i.e., aneurysm in which it is to be deployed.
Thus, confinement of the device within an aneurysm causes it to assume a three-dimensional
configuration with a higher energy state than the minimum energy state. Because the
minimum energy state configuration of the device is larger in at least one dimension
than the aneurysm, the deployed device is constrained by its contact with the walls
of the aneurysm from returning to its minimum energy state configuration. The engagement
of the device with the aneurysm wall minimizes shifting or tumbling due to blood flow.
Furthermore, the secondary configuration is not conducive to "coin stacking," thereby
minimizing the compaction experienced.
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